1/*
2 * Backlight driver for OMAP based boards.
3 *
4 * Copyright (c) 2006 Andrzej Zaborowski  <balrog@zabor.org>
5 *
6 * This package is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This package is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this package; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19 */
20
21#include <linux/module.h>
22#include <linux/kernel.h>
23#include <linux/init.h>
24#include <linux/platform_device.h>
25#include <linux/fb.h>
26#include <linux/backlight.h>
27#include <linux/slab.h>
28#include <linux/platform_data/omap1_bl.h>
29
30#include <mach/hardware.h>
31#include <mach/mux.h>
32
33#define OMAPBL_MAX_INTENSITY		0xff
34
35struct omap_backlight {
36	int powermode;
37	int current_intensity;
38
39	struct device *dev;
40	struct omap_backlight_config *pdata;
41};
42
43static inline void omapbl_send_intensity(int intensity)
44{
45	omap_writeb(intensity, OMAP_PWL_ENABLE);
46}
47
48static inline void omapbl_send_enable(int enable)
49{
50	omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
51}
52
53static void omapbl_blank(struct omap_backlight *bl, int mode)
54{
55	if (bl->pdata->set_power)
56		bl->pdata->set_power(bl->dev, mode);
57
58	switch (mode) {
59	case FB_BLANK_NORMAL:
60	case FB_BLANK_VSYNC_SUSPEND:
61	case FB_BLANK_HSYNC_SUSPEND:
62	case FB_BLANK_POWERDOWN:
63		omapbl_send_intensity(0);
64		omapbl_send_enable(0);
65		break;
66
67	case FB_BLANK_UNBLANK:
68		omapbl_send_intensity(bl->current_intensity);
69		omapbl_send_enable(1);
70		break;
71	}
72}
73
74#ifdef CONFIG_PM_SLEEP
75static int omapbl_suspend(struct device *dev)
76{
77	struct backlight_device *bl_dev = dev_get_drvdata(dev);
78	struct omap_backlight *bl = bl_get_data(bl_dev);
79
80	omapbl_blank(bl, FB_BLANK_POWERDOWN);
81	return 0;
82}
83
84static int omapbl_resume(struct device *dev)
85{
86	struct backlight_device *bl_dev = dev_get_drvdata(dev);
87	struct omap_backlight *bl = bl_get_data(bl_dev);
88
89	omapbl_blank(bl, bl->powermode);
90	return 0;
91}
92#endif
93
94static int omapbl_set_power(struct backlight_device *dev, int state)
95{
96	struct omap_backlight *bl = bl_get_data(dev);
97
98	omapbl_blank(bl, state);
99	bl->powermode = state;
100
101	return 0;
102}
103
104static int omapbl_update_status(struct backlight_device *dev)
105{
106	struct omap_backlight *bl = bl_get_data(dev);
107
108	if (bl->current_intensity != dev->props.brightness) {
109		if (bl->powermode == FB_BLANK_UNBLANK)
110			omapbl_send_intensity(dev->props.brightness);
111		bl->current_intensity = dev->props.brightness;
112	}
113
114	if (dev->props.fb_blank != bl->powermode)
115		omapbl_set_power(dev, dev->props.fb_blank);
116
117	return 0;
118}
119
120static int omapbl_get_intensity(struct backlight_device *dev)
121{
122	struct omap_backlight *bl = bl_get_data(dev);
123
124	return bl->current_intensity;
125}
126
127static const struct backlight_ops omapbl_ops = {
128	.get_brightness = omapbl_get_intensity,
129	.update_status  = omapbl_update_status,
130};
131
132static int omapbl_probe(struct platform_device *pdev)
133{
134	struct backlight_properties props;
135	struct backlight_device *dev;
136	struct omap_backlight *bl;
137	struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);
138
139	if (!pdata)
140		return -ENXIO;
141
142	bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
143			  GFP_KERNEL);
144	if (unlikely(!bl))
145		return -ENOMEM;
146
147	memset(&props, 0, sizeof(struct backlight_properties));
148	props.type = BACKLIGHT_RAW;
149	props.max_brightness = OMAPBL_MAX_INTENSITY;
150	dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,
151					bl, &omapbl_ops, &props);
152	if (IS_ERR(dev))
153		return PTR_ERR(dev);
154
155	bl->powermode = FB_BLANK_POWERDOWN;
156	bl->current_intensity = 0;
157
158	bl->pdata = pdata;
159	bl->dev = &pdev->dev;
160
161	platform_set_drvdata(pdev, dev);
162
163	omap_cfg_reg(PWL);	/* Conflicts with UART3 */
164
165	dev->props.fb_blank = FB_BLANK_UNBLANK;
166	dev->props.brightness = pdata->default_intensity;
167	omapbl_update_status(dev);
168
169	dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");
170
171	return 0;
172}
173
174static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
175
176static struct platform_driver omapbl_driver = {
177	.probe		= omapbl_probe,
178	.driver		= {
179		.name	= "omap-bl",
180		.pm	= &omapbl_pm_ops,
181	},
182};
183
184module_platform_driver(omapbl_driver);
185
186MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
187MODULE_DESCRIPTION("OMAP LCD Backlight driver");
188MODULE_LICENSE("GPL");
189